// Copyright (c) 1996-2009 Nokia Corporation and/or its subsidiary(-ies).

 // All rights reserved.

 // This component and the accompanying materials are made available

 // under the terms of the License "Eclipse Public License v1.0"

 // which accompanies this distribution, and is available

 // at the URL "http://www.eclipse.org/legal/epl-v10.html".

 //

 // Initial Contributors:

 // Nokia Corporation - initial contribution.

 //

 // Contributors:

 //

 // Description:

 // f32\sfat32\inc\sl_cache.inl

 // 

 //

 /**

  @file

  @internalTechnology

 */

 #ifndef SL_CACHE_INL

 #define SL_CACHE_INL

 /**

     @param  aPos media linear position

     @return ETrue if the aPos belongs to this page

 */

 TBool CWTCachePage::PosCached(TInt64 aPos) const

     {

     return (iValid && aPos >= iStartPos && aPos < iStartPos+PageSize());

     }

 /**

     Calculate data position within cache page relatively to the page beginning.

     @param  aPos media linear position

     @return data offset from the beginning of the page

 */

 TUint32 CWTCachePage::PosInCachePage(TInt64 aPos) const 

     { 

     return ((TUint32)aPos - (TUint32)iStartPos) & (PageSize()-1);

     }

 /**

     Obtain pointer to the data in the cache page by media inear position

     @param  aPos media linear position

     @return pointer to the data in page buffer

 */

 TUint8* CWTCachePage::PtrInCachePage(TInt64 aPos) const 

     { 

     return (TUint8*)iData.Ptr() + PosInCachePage(aPos);

     }

 /**

     @return cache page size in bytes

 */

 TUint32 CWTCachePage::PageSize() const 

     {

     return iData.Size();

     }  

 //---------------------------------------------------------------------------------------------------------------------------------

 /**

     Just helper method to calculate cache page start position by given media pos.

     @param  aPos media linear position

     @return rounded-down and aligned position that is the beginning of the cache page

 */

 TInt64  CMediaWTCache::CalcPageStartPos(TInt64 aPos) const 

     { 

     ASSERT(aPos >= iCacheBasePos);

     return (((aPos - iCacheBasePos) >> iPageSizeLog2) << iPageSizeLog2) + iCacheBasePos;

     }

 /**

     @return cache page size

 */

 TUint32 CMediaWTCache::PageSize() const 

     {

     return 1<<iPageSizeLog2;

     }

 /**

     Set cache base position at aBasePos

     @param  aBasePos  base position of the cache pages. Affects pages alignment.

 */

 void CMediaWTCache::SetCacheBasePos(TInt64 aBasePos)

     {

     iCacheBasePos = aBasePos;

     }

 //---------------------------------------------------------------------------------------------------------------------------------

 #endif //SL_CACHE_INL